From the prior art it is known that fluids such as water or air can be sterilized by ultraviolet (UV) radiation. The fluid to be sterilized is therefore exposed to a source of UV radiation for a specific time.
CH 477 825 shows a device for sterilizing a fluid by UV radiation. The fluid is exposed to UV radiation in a gap between an inner and an outer tube which are arranged concentrically to each other. In the gap between the inner and the outer tube turbulence generating elements are arranged to prevent laminar flow of the fluid. The tube in which the UV-lamp is arranged is closed on one end.
U.S. Pat. No. 6,402,926 shows a device for sterilizing a fluid with a removable UV lamp. The fluid to be treated is guided through a gap between an inner and outer tube wherein a spiral-shaped device is arranged in this gap preventing laminar flow of the fluid. The outer tube is straight or U-shaped and the inner tube, in which the UV-lamp is arranged, is made of UV-transparent material and is closed on one end.
WO 00/14018 is directed to a sterilizing device for a fluid. The sterilizing device comprises a first and a second sleeve which are arranged on opposite ends of an outer tube. In the outer tube an inner tube is arranged concentrically. The inner tube which forms the housing for the UV-lamp is made of UV-transparent material and is closed on one end. The sleeves and/or the tube are made out of plastic or aluminum.
U.S. Pat. No. 6,693,397 shows a lamp source device which emits illuminating light in an endoscope. The device unit comprises a housing that includes a CPU for measuring the illumination time of the light-source and an antenna for sending the illumination time measured by the CPU to the lamp unit. The lamp unit comprises a housing for a Xenon-Lamp. An RFID tag is fixed to the housing of the lamp. The RFID tag has an antenna for receiving the illumination time information sent from the antenna of the housing and a rewriteable memory for storing the illumination time information received by the antenna of the tag.
WO 00/78678 discloses a water treatment system comprising an inductively coupled ballast circuit, a first subunit in the form of a UV-lamp-unit and a second subunit in the form of a filter unit. The water treatment system is designed for end of pipe and table units, only for small amounts of water. The water does not
The UV-lamp-unit is inductively coupled for non-contact power transfer. The radio frequency identification system includes an ultraviolet light transponder that is located in the ultraviolet lamp assembly. In addition, the radio frequency identification system includes a filter transponder that is located in the filter assembly. The ultraviolet light transponder and the filter transponder communicate, using radio frequency, with the radio frequency identification system. Each transponder contains certain information that is specific to the ultraviolet lamp assembly and the filter assembly. Alternatively a non-wireless identification system may be used instead of the radio frequency identification system.
WO 00/78678 is directed to an electronic control system for a water treatment system that includes an inductively coupled ballast circuit. The water treatment system filters water by, amongst other things, directing a flow of water from a water supply to a filter assembly. The filter assembly removes unwanted particulates from the flow of water. After passing through the filter assembly, the water is directed to a replaceable ultraviolet lamp assembly. The ultraviolet lamp assembly destroys organic matter in the supply of water by exposing the water to high-intensity ultraviolet light as the water flows through the ultraviolet lamp assembly. The overall operation of the water treatment system is controlled by a control unit that is electrically connected with the ultraviolet lamp assembly and the filter assembly. In the preferred embodiment, the control unit is also electrically connected with a flow sensor, an ambient temperature sensor circuit, an ambient light sensor circuit, an ultraviolet light sensor circuit, a power detection circuit, a display, an audio generation circuit, a memory storage device, a communications port and a radio frequency identification system. These devices are all monitored or controlled by the control unit.
The devices known from the prior art are using specific UV-lamps as available on the marked and are therefore in general committed to one type only. Due to the reason that common UV-lamps are subjected to aging, which results in a decreasing performance of the UV-lamps, they have to be replaced frequently to guarantee save sterilization of the fluid. To reduce the risk of insufficient disinfection of the fluid the UV-lamps are replaced after a certain period of time even though they have not yet achieved the end of their lifetime. In the case of failure of the source of radiation e.g. by contamination of the source of radiation, by oxidation of contacts or maltreatment, the devices known from the state of the art do not offer the opportunity to indicate such incident. Therefore these devices carry a relatively high burden of risk and are therefore very cost intensive due to frequent maintenance and early replacement of the source of radiation to guarantee save function. Higher reliability is tried to be achieved by more expensive UV-lamps resulting in the draw back of higher operating costs.